Telephone ringing system for party-lines.



G. A. SIMPSON. a'nnnrnonn meme sYs'rnn 1-01; mm Luna.

I APPLICATION nun luv. ao,-1oo1. 91 0,87 3.

Patented Jan. 26, 1909.

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wxvnasm UNITED STATES PATENT OFFICE.

CHARLES A. SIMPSON, OF CHICAGO, ILLINOIS ii SSIGNOR TO KELLOGUSWITCHBOARD AND SUPPLY GGMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OFILLINOIS.

TELEPHONE BINGING' SYSTEM FOR PARTY-LINES.

Patented Jan. 26, 1909 Application filed November 30, 1907.' Serial No.404,684.

To all whom it may concern:

Be it known that I, CHAnLns A. SIMPSON, a citizen of the United States,residing in Chicago, county of Cook, and State of lllinois, haveinvented certain new and useful Imrovements in Telephone Rin ing Systemsor Party-Lines, of which the ollowing is a specification.

My invention relates to part line telephone systems, and more particuarly to that class of s stems havin a bridged clearingout signa at thecentre oilicc adapted to be actuated at the end of a conversation bycurrent sent from a hand generator at tho subscribers station. Insystcmsof this class it has become the practice to connect a number ofsubscribers instruments in parallel across the same telephone line.These instruments are each provided with a signaling bell, and in the sstem to which my invention particu larly re ates each bell is connectedin series with a condenser of suflicient ca acity to pass the ringingcurrent for the bel With former systems of this character, when theoperator at the central oflice rung one of the bells -nn a line, shesimultaneously charged and 1 scli arged all of the condensers wh ch werebridged across the line at the difi'crent substations. If in thesesystcn'is, the 0 erator released her ringing key at a time W ion thecondensers of the various substations were highly charged, the dischargeof these condensers would take place after the ringin key had returnedto its normal osition ans would therefore pass through tie clearingoutsignal and momentarily energize that signal, causing it to be displayed.

It is the object of my present invention to overcome the difiicultyexperienced from the discharge current from these condensers, andthereby to provide a circuit which is more crfect in operation and lessliable to give alse signals than systems used in the past.

Other objects of my invention will be brought out in the Followingdescription and claims.

My invention is illustrated in the accom- 'panying drawing in which aline having but one subscriber thereon is illustrated at the left handside of the drawing, and a party line havin four subscribers thereon isillustrated at t ie right hand side of the drawing, thetwo bein adaptedto be connected for conversation by the central oflicc ap )aratus.

The calling subscribers station No. 1 is e nipped with the usualapparatus consistin o? the transmitter 2, battery 3, induction CO1 and,generator 8, and in addition'thereto, the condenser 9 which is connectedermanently in series with the apparatus of tie set. The rare wires 10and 11 extend from the subscribers station 1 to the central oilioe wherethe T pass through the series contacts 12, 13 and 14: of the answcrinand multiple jacks and terminate in the COl l of the line dro 15. Thecalled subscribers line is similhrly equi ped, corresponding apparatusof this line sing dcsignat by like figures with the suffix The cordcircuit for connecting the lines for conversation has the tip and ringconductors 18 and 19, each being respectively interrupted by condensers20 and 21. The sle ve conductors 22 and 28 of the answering switch hook5, receiver 6, annunciator 7 and calling cords are connected with thelive pole of battery A through the non-inductive resistance 24. Theclearing out signals in thesystem hero shown consist of the relayshaving the high resistance windings 25 and 26, one bridged across eachend of the cord circuit, these relays being provided with thelock-windings 27 and 28 and with the con tacts 29 and 30 in the circuitsof the clearing out lamps 31 and 32 The spring contacts of the twoclearing out relays are connected together by conductor 33, thisconductor bemg connected through the auxiliary contact 34 of theoperator s listening key 35 to earth. It is customary in a four-partyringing system of the type here shown to use four separate sources ofcurrent 36, each adapted to be connected with the desired linethroughthe contacts of the ringing key. These four ringing keys are connectedin scrics, such that the actuation of one of the keys disconnects theplug of the calling cord from the other apparatus of the cord circuit,

live pole of battery A. Relay 42 controls the normally open'contacts 44and 45, contact 44 being permanently connected with the sleeve strand ofthe cord circuit and contact being permanently connected with the tipstrand of the cord circuit at a point back of the series contacts of theringing key. In the operation of my system the calli subscriber turnsher hand generator 8 an sends a current over conductors 10 and 11through the series contacts 14,. 13 and 12 of the jacks and through thecoil of the line drop 15, throwing the drop and indicating to theoperator tha. a connection is desired. The operator therefore insertsher calling lug 16 into the jack indicated, throws her istening key 35and inquires the desired number. The number being obtained, the operatortests the desired line in' the usual manner. If the line is busy itssleeve contact will be at a potential higher than that of earth and acurrent will flow over the tip of the cord and throu h the operatorshead receiver and the thin? conductor connected therewith to earthgiving a click and indicating the busy condition. Considering,

however, that the line is idle, the operator inserts her calling plug 17and actuat'es the key which is adapted to ring the bell at thedesrredsubscriber s station. The actuation of this key closes the circuit fromthe generator over the tip contacts of the plug and jack, line conductor11, condensers 9', annunciators 7, line conductor 10', the ring contactsof the j ack and plug, the spring 39 of the operators ringing key andcontact 41 to earth. At the same time current will flow from the batteryA through onductor 43, the coil of relay 42, contact 40, pring 39 andcontact 41 to earth, thereby actuating relay 42 and closin its contacts44 and 45 thus com leting as out between the ti and ring con uctors ofthe cord circuit. pon the release of the operator's key the stored upene from thecon enser's 9' is allowed to disc arge over the lineconductors 10' and 11, the tip and ring contacts of.;

the jack and plug, the series contacts of the operator's ringing keyand'the shunting contacts 45 and 44 of relay 42. This prevents currentfrom these condensersfrom passing through the actuating coil 26 ofdisconnect relay. The relay 42 is preferably made. slow acting by any ofthe well known methods such as inclosing its core in the copper shell.37.

When the conversation has been terminated the subscriber's rotate theirhand generators 'and thereby send current over the line conductors andtmough the coils 25 and 26 of the disconnect relays associatedrespectivel with the answering and ulallrng ends of t e cord circuit.When these relays are actuated the circuit is com leted from the livepole of battery A throng the lamps 32 and 31 and through the contacts 29and 30 and the contact 34 of the operator's listemng key to ground, thusdisplayin the lam 32 and 31 A circuit is sirnu taneous y completed fromthe live pole of battery A through the locking coils 27 and 28 of thedisconnect relays an through the contacts 34 of the operators listeningkey to earth. The operator seeing the signals 3.1 and 32. displayedremoves her answering and calling plugs from the jacks of the line andthen presses her listening key opening the con tacts 34 and releasingthe disconnect signals 31 and 32. The lines are now again in theirnormal condition and ready for a second call.

It is to be understood that the clearing out signals here shown anddescribed are of typical form and may be simp}y ordinary c caring outdropsor may be 0 any other desired form, and that many other variationsfrom the system shown and described may be made without departing fromthe spirit or scope of my invention.

I claim:

1. In a telephone system, the combination with a telephone line having abridged condenser thereon, of a cord circuit to connect therewith havmga. bridged clearing out signal, a source of ringing current at thecentral office, means to connect said source with the' telephone linefor signaling, and means to divert the discharge current from saidcondenser from the coil of said clearing out signal after ringing,scribed.

2. In a telephone system, the combination with a telephone line having abridged condenser and annunciator, of a cord circuit to connecttherewith ha a clearing out signal, a source of ringing current, andneans to connect said soiurce with the line or si na' u oses, an meansto revent the d isch d r gd c ib-rent from said cohdenser from passingthrough said clearing out signal after ringin substantially asdescribed.

3. In a te ephone system, the combination with a telephoneline having abridged condenser, of a cord circuit to connect therewith havi a bridgedclearing out signal, a source of ringing current, a ringing key andmeans to complete a shunt about the coil of said clearing out signalto'receive the discharge current from said condensers after ringrnig,substantially as described.

4. n a telephone system, the combination with a telephoneline having abridged condenser, of a cord circuit having a bridged clearing outsignal, a source of ringing current, a ringing key and means operated bythe actuation of said key for cornpleting a circuit for the dischargecurrent of said condensers after ringing, substantially as described.

5. In a telephone system, the combination with a telephone line having abridged condenser, of a cord circuit having a bridged substantially asdeclearing out sigfial, a splurc lof 'ng gurrent a ringing ey an a re aya apte to a chest siaost the steering out sighal or a short time afterring substantially as described.

6. In a telephone system, thecombination with a line having ca acity, ofa cord circuit ,cord circuit having a signal receiving device, a rmgmgkey, a relay, said key having contacts in the circuit of the coil ofsaid relay,

and said relay having contacts in the circuit ol' the discharge currentfrom said capacity, substantiallv as described.

8. In a telephone system, the combination witha telephone line havincapacity, of a cord circuit having a brii ged signal receiving device,means to charge the capacity of the line and means to divert thedischarge current from the line from the brid ed si nal receivingdevice, substantially as eseri ed.

9. In a telephone system, thecombination with a telephone line havingreactance of a signal recelvin device connected with said time whichcould be actuated by an impulse of reactance current, and means toprevent the reactance current from the line from passing through said sinal receiving device, substantially as dBSCII ed.

10. In a telephone system, the combination with a telephone line havincapacity, of a'signal receiving device bridge between the lim s of theline at the central office adapted to be locked in actuated condition byan impulse ofcurrent, and means to prevent the discharge current fromsaid ca acity from actuating said signal, substantially as described.

11 In a telephone system, the combination with a telephone line havingreactance, of a signal receiving device having its coil bridged betweenthe limbs of said line at the central office, and means to prevent thereactance current from the line from passing through said si alreceiving device, substantially as descri ed.

12. In a tele hone system, the combinatibn with a cor circuit, of asignaling device associated therewith, and a slow-acting rela adapted byits retarded action to maintain a shunt about the coil of said signalingdevice for a short duration of time, substantially as described.

13. In a tele hone system, the combination with a telep lione linehaving a reactance, of a cord circuit adapted to connect there with, asignal receivin device associated with the cord circuit an a slow-actingrelay adapted by its retarded action to prevent the reactance currentfrom the line from passing through said si al receiving device,substantially as descri ed.

14. In a telephone system, the combination with a telephone line of acord circuit to connect therewith, a ringing key for the cord circuit, abridged signal recelvmg device, and means to maintain a shunt about thecoil of said signal receiving de vice for a short duration of time afterthe ringing key has been returned to its normal position, substantiallyas described.

15. In a tele 'hone s 'stem, the combination with a cor circuit aving abridged signal receiving device, a ringing key for the cord circuit aslow-acting relay adapted to be ener ized by the actuation of saidringing key an the actuation of said slow-acting relay being adapted tocomplete ashunt about the coil of said bridged signal receiving device,substantiall Y as described.

16. In a telep lone system, the combination with a telephone line havingrcactance, of a locking relay at the central ol'lice, a signalcr.-.nt1'olld by said relay, and means to )10- vent the reactancecurrent from said his from actuating said relay, substantially asdescribed.

17. In a telephone system, the combination with a cord circuit, of alocking relay having its initial operatin coil bridged across the line,a second coil therefor adapted to be energized over a local circuit tomaintain the actuation of said relay, and means to prevent dischargecurrent from the line from initially actuating said relay, substantiallyas described. a

Signed by me at Chica 0, county of Cook, and State of Illinois, in t ispresence of two witnesses.

CHARLES A. SIMPSON. Witnesses:

CLIFFORD C. Bnann'oar MAR-loam E. Game.

